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Finding the Fourth Proportional to 811, 1,216.80 and 486.60

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Solution

The fourth proportional to 811, 1,216.80 and 486.60 is: 730.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    811 : 1,216.80 = 486.60 : x
  2. Step 2: Convert to fraction form
    811/1,216.80 = 486.60/x
  3. Step 3: Cross multiply
    811x = 1,216.80 × 486.60
  4. Step 4: Simplify right side
    811x = 592,094.88
  5. Step 5: Solve for x
    x = 592,094.88/811
  6. Step 6: Final answer
    x = 730.08

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.